Long Term Objectives: To test and make commercially available, an already defined laboratory process for impregnating antimicrobial agents into silicone rubber. Successful results from the current study models, (cerebro-spinal fluid shunts and central venous catheters) will later be applied to many commercial devices which bring silicone rubber into chronic contact with living body tissue. It is expected that major humanitarian benefits will result because of lowered incidence of infection due to this innovation. Phase II -Specific Aims: 1. To conclude pre-clinical testing in vitro, (demonstration of protection against colonization, quantitation of antimicrobials in perfused catheters) and in vivo (mouse intra-cerebral implant, dog intravenous catheter implant, quantitation of antimicorbial levels in serum and urine) jointly in a central venous catheter and in the Denver Hydrocephalus Shunt. 2. To complete a clinical trial with impregnated central venous catheters and thereby meet the FDA requirements for pre-market approval of the product. In Phase III an antimicrobial-impregnated central venous catheter will be made commercially available and a clinical trial will be initiated with antimicrobial impregnated Denver Hydrocephalus Shunts.